tetris.css

div.tetrisGame {
  position: relative;
  margin: 0;
  padding: 0;
  border: none;
  width: 600px;
  height: 600px;
}

div.tetrisGame div.tetrisLeftPane {
  position: absolute;
  top: 0;
  left: 0;
  width: 300px;
}

div.tetrisLeftPane div.tetrisScore {
  position: absolute;
  top: 150px;
  left: 0;
  font-size: 20pt;
}

div.tetrisLeftPane div.tetrisPreview {
  position: absolute;
  left: 150px;
  width: 120px;  /* 4 cols * 30px */
  height: 120px;  /* 4 rows * 30px */
}

div.tetrisLeftPane div.tetrisUsage {
  position: absolute;
  left: 0;
  top: 300px;
}

div.tetrisLeftPane div.tetrisUsage th,
div.tetrisLeftPane div.tetrisUsage td {
  text-align: left;
}

div.tetrisLeftPane div.tetrisUsage td {
  padding-left: 1em;
}

div.tetrisRightPane {
  position: absolute;
  left: 300px;
  top: 0px;
  width: 300px;  /* 10 cols * 30px */
  height: 600px;  /* 20 rows * 30px */
}

div.tetrisRightPane div.tetrisBoard {
  position: absolute;
  left: 0;
  top: 0;
  width: 300px;  /* 10 cols * 30px */
  height: 600px;  /* 20 rows * 30px */
}

div.tetrisBlock {
  position: absolute;
  width: 29px;
  height: 29px;
  border: 1px solid black;
  background-color: black;
}

div.tetrisBlock.habitated {
  border: 1px solid black;
  background-color: gray;
}